1994 Fiscal Year Final Research Report Summary
Study on Activities and Discrimination of Heads of the Muscle Contractile Protein Myosin by Means of Fluorescence and Laser Photolysis Methods
| Project/Area Number |
05640646
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機能・物性・材料
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| Research Institution | Gunma University |
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Principal Investigator |
KOBASHI Harumichi Gunma University ASSOCIATE PROFESSOR, 工学部, 助教授 (80008515)
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| Co-Investigator(Kenkyū-buntansha) |
EIKI Toshio Gunma University ASSOCIATE PROFESSOR, 工学部, 助教授 (60143202)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Myosin / Fluorescent Probe / Noncovalently Bonding Probe / Covalently bonding Prove / SH-Modification / NH_2-Modification / Pyrene Derivatives / Trinitrophenylation |
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| Research Abstract |
The present research project aimed to elucidate fluorescence behavior of pyrene (P) derivatives which are expected as useful probes for obtaining informations concerning microstructure and functions of M,especially in relation to discrimination of two myosin heads.
1. Binding constants of P and 1-pyrenesulfonate ion (PS) with M were estimated to be 4.9x10^5 and 1x10^7 M^<-1>, respectively, in aq soln (pH 7.0) at 20ﾟC
2. Pyrene molecules of <greater than or equal> 65% fraction were located in inner hydrophobic regions of M where iodide ion as quencher can not quench the fluorescence of P.PS binds with M in a relatively hydrophillic region accessible to the
3. .Some fluorescent probes with a pyrene chromophore react specifically with active SH-or NH_2-groups of M.Myosin modified with N- (1-pyrene) iodoacetamide showed a typical curve in pH dependence of Ca-ATPase activity of SH1-modified M.Change in fluorescence characteristics of the probe was observed associated with conformational change of M induced by the addition of ATP.
4. Trinitrophenylation and retrinitrophenylation with 2,4,6-trinitrobenzenesulfonic acid revealed that the two heads of chicken skeletal M were different from each other in pH dependence of Ca-ATPase activity and in reactivities in the presence and absence of PPi. These findings suport the hypothesis of non-identical heads.
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